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// Copyright 2016 The etcd Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package clientv3
import pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
type opType int
const (
// A default Op has opType 0, which is invalid.
tRange opType = iota + 1
tPut
tDeleteRange
tTxn
)
var noPrefixEnd = []byte{0}
// Op represents an Operation that kv can execute.
type Op struct {
t opType
key []byte
end []byte
// for range
limit int64
sort *SortOption
serializable bool
keysOnly bool
countOnly bool
minModRev int64
maxModRev int64
minCreateRev int64
maxCreateRev int64
// for range, watch
rev int64
// for watch, put, delete
prevKV bool
// for watch
// fragmentation should be disabled by default
// if true, split watch events when total exceeds
// "--max-request-bytes" flag value + 512-byte
fragment bool
// for put
ignoreValue bool
ignoreLease bool
// progressNotify is for progress updates.
progressNotify bool
// createdNotify is for created event
createdNotify bool
// filters for watchers
filterPut bool
filterDelete bool
// for put
val []byte
leaseID LeaseID
// txn
cmps []Cmp
thenOps []Op
elseOps []Op
}
// accessors / mutators
// IsTxn returns true if the "Op" type is transaction.
func (op Op) IsTxn() bool {
return op.t == tTxn
}
// Txn returns the comparison(if) operations, "then" operations, and "else" operations.
func (op Op) Txn() ([]Cmp, []Op, []Op) {
return op.cmps, op.thenOps, op.elseOps
}
// KeyBytes returns the byte slice holding the Op's key.
func (op Op) KeyBytes() []byte { return op.key }
// WithKeyBytes sets the byte slice for the Op's key.
func (op *Op) WithKeyBytes(key []byte) { op.key = key }
// RangeBytes returns the byte slice holding with the Op's range end, if any.
func (op Op) RangeBytes() []byte { return op.end }
// Rev returns the requested revision, if any.
func (op Op) Rev() int64 { return op.rev }
// IsPut returns true iff the operation is a Put.
func (op Op) IsPut() bool { return op.t == tPut }
// IsGet returns true iff the operation is a Get.
func (op Op) IsGet() bool { return op.t == tRange }
// IsDelete returns true iff the operation is a Delete.
func (op Op) IsDelete() bool { return op.t == tDeleteRange }
// IsSerializable returns true if the serializable field is true.
func (op Op) IsSerializable() bool { return op.serializable == true }
// IsKeysOnly returns whether keysOnly is set.
func (op Op) IsKeysOnly() bool { return op.keysOnly == true }
// IsCountOnly returns whether countOnly is set.
func (op Op) IsCountOnly() bool { return op.countOnly == true }
// MinModRev returns the operation's minimum modify revision.
func (op Op) MinModRev() int64 { return op.minModRev }
// MaxModRev returns the operation's maximum modify revision.
func (op Op) MaxModRev() int64 { return op.maxModRev }
// MinCreateRev returns the operation's minimum create revision.
func (op Op) MinCreateRev() int64 { return op.minCreateRev }
// MaxCreateRev returns the operation's maximum create revision.
func (op Op) MaxCreateRev() int64 { return op.maxCreateRev }
// WithRangeBytes sets the byte slice for the Op's range end.
func (op *Op) WithRangeBytes(end []byte) { op.end = end }
// ValueBytes returns the byte slice holding the Op's value, if any.
func (op Op) ValueBytes() []byte { return op.val }
// WithValueBytes sets the byte slice for the Op's value.
func (op *Op) WithValueBytes(v []byte) { op.val = v }
func (op Op) toRangeRequest() *pb.RangeRequest {
if op.t != tRange {
panic("op.t != tRange")
}
r := &pb.RangeRequest{
Key: op.key,
RangeEnd: op.end,
Limit: op.limit,
Revision: op.rev,
Serializable: op.serializable,
KeysOnly: op.keysOnly,
CountOnly: op.countOnly,
MinModRevision: op.minModRev,
MaxModRevision: op.maxModRev,
MinCreateRevision: op.minCreateRev,
MaxCreateRevision: op.maxCreateRev,
}
if op.sort != nil {
r.SortOrder = pb.RangeRequest_SortOrder(op.sort.Order)
r.SortTarget = pb.RangeRequest_SortTarget(op.sort.Target)
}
return r
}
func (op Op) toTxnRequest() *pb.TxnRequest {
thenOps := make([]*pb.RequestOp, len(op.thenOps))
for i, tOp := range op.thenOps {
thenOps[i] = tOp.toRequestOp()
}
elseOps := make([]*pb.RequestOp, len(op.elseOps))
for i, eOp := range op.elseOps {
elseOps[i] = eOp.toRequestOp()
}
cmps := make([]*pb.Compare, len(op.cmps))
for i := range op.cmps {
cmps[i] = (*pb.Compare)(&op.cmps[i])
}
return &pb.TxnRequest{Compare: cmps, Success: thenOps, Failure: elseOps}
}
func (op Op) toRequestOp() *pb.RequestOp {
switch op.t {
case tRange:
return &pb.RequestOp{Request: &pb.RequestOp_RequestRange{RequestRange: op.toRangeRequest()}}
case tPut:
r := &pb.PutRequest{Key: op.key, Value: op.val, Lease: int64(op.leaseID), PrevKv: op.prevKV, IgnoreValue: op.ignoreValue, IgnoreLease: op.ignoreLease}
return &pb.RequestOp{Request: &pb.RequestOp_RequestPut{RequestPut: r}}
case tDeleteRange:
r := &pb.DeleteRangeRequest{Key: op.key, RangeEnd: op.end, PrevKv: op.prevKV}
return &pb.RequestOp{Request: &pb.RequestOp_RequestDeleteRange{RequestDeleteRange: r}}
case tTxn:
return &pb.RequestOp{Request: &pb.RequestOp_RequestTxn{RequestTxn: op.toTxnRequest()}}
default:
panic("Unknown Op")
}
}
func (op Op) isWrite() bool {
if op.t == tTxn {
for _, tOp := range op.thenOps {
if tOp.isWrite() {
return true
}
}
for _, tOp := range op.elseOps {
if tOp.isWrite() {
return true
}
}
return false
}
return op.t != tRange
}
// OpGet returns "get" operation based on given key and operation options.
func OpGet(key string, opts ...OpOption) Op {
ret := Op{t: tRange, key: []byte(key)}
ret.applyOpts(opts)
return ret
}
// OpDelete returns "delete" operation based on given key and operation options.
func OpDelete(key string, opts ...OpOption) Op {
ret := Op{t: tDeleteRange, key: []byte(key)}
ret.applyOpts(opts)
switch {
case ret.leaseID != 0:
panic("unexpected lease in delete")
case ret.limit != 0:
panic("unexpected limit in delete")
case ret.rev != 0:
panic("unexpected revision in delete")
case ret.sort != nil:
panic("unexpected sort in delete")
case ret.serializable:
panic("unexpected serializable in delete")
case ret.countOnly:
panic("unexpected countOnly in delete")
case ret.minModRev != 0, ret.maxModRev != 0:
panic("unexpected mod revision filter in delete")
case ret.minCreateRev != 0, ret.maxCreateRev != 0:
panic("unexpected create revision filter in delete")
case ret.filterDelete, ret.filterPut:
panic("unexpected filter in delete")
case ret.createdNotify:
panic("unexpected createdNotify in delete")
}
return ret
}
// OpPut returns "put" operation based on given key-value and operation options.
func OpPut(key, val string, opts ...OpOption) Op {
ret := Op{t: tPut, key: []byte(key), val: []byte(val)}
ret.applyOpts(opts)
switch {
case ret.end != nil:
panic("unexpected range in put")
case ret.limit != 0:
panic("unexpected limit in put")
case ret.rev != 0:
panic("unexpected revision in put")
case ret.sort != nil:
panic("unexpected sort in put")
case ret.serializable:
panic("unexpected serializable in put")
case ret.countOnly:
panic("unexpected countOnly in put")
case ret.minModRev != 0, ret.maxModRev != 0:
panic("unexpected mod revision filter in put")
case ret.minCreateRev != 0, ret.maxCreateRev != 0:
panic("unexpected create revision filter in put")
case ret.filterDelete, ret.filterPut:
panic("unexpected filter in put")
case ret.createdNotify:
panic("unexpected createdNotify in put")
}
return ret
}
// OpTxn returns "txn" operation based on given transaction conditions.
func OpTxn(cmps []Cmp, thenOps []Op, elseOps []Op) Op {
return Op{t: tTxn, cmps: cmps, thenOps: thenOps, elseOps: elseOps}
}
func opWatch(key string, opts ...OpOption) Op {
ret := Op{t: tRange, key: []byte(key)}
ret.applyOpts(opts)
switch {
case ret.leaseID != 0:
panic("unexpected lease in watch")
case ret.limit != 0:
panic("unexpected limit in watch")
case ret.sort != nil:
panic("unexpected sort in watch")
case ret.serializable:
panic("unexpected serializable in watch")
case ret.countOnly:
panic("unexpected countOnly in watch")
case ret.minModRev != 0, ret.maxModRev != 0:
panic("unexpected mod revision filter in watch")
case ret.minCreateRev != 0, ret.maxCreateRev != 0:
panic("unexpected create revision filter in watch")
}
return ret
}
func (op *Op) applyOpts(opts []OpOption) {
for _, opt := range opts {
opt(op)
}
}
// OpOption configures Operations like Get, Put, Delete.
type OpOption func(*Op)
// WithLease attaches a lease ID to a key in 'Put' request.
func WithLease(leaseID LeaseID) OpOption {
return func(op *Op) { op.leaseID = leaseID }
}
// WithLimit limits the number of results to return from 'Get' request.
// If WithLimit is given a 0 limit, it is treated as no limit.
func WithLimit(n int64) OpOption { return func(op *Op) { op.limit = n } }
// WithRev specifies the store revision for 'Get' request.
// Or the start revision of 'Watch' request.
func WithRev(rev int64) OpOption { return func(op *Op) { op.rev = rev } }
// WithSort specifies the ordering in 'Get' request. It requires
// 'WithRange' and/or 'WithPrefix' to be specified too.
// 'target' specifies the target to sort by: key, version, revisions, value.
// 'order' can be either 'SortNone', 'SortAscend', 'SortDescend'.
func WithSort(target SortTarget, order SortOrder) OpOption {
return func(op *Op) {
if target == SortByKey && order == SortAscend {
// If order != SortNone, server fetches the entire key-space,
// and then applies the sort and limit, if provided.
// Since by default the server returns results sorted by keys
// in lexicographically ascending order, the client should ignore
// SortOrder if the target is SortByKey.
order = SortNone
}
op.sort = &SortOption{target, order}
}
}
// GetPrefixRangeEnd gets the range end of the prefix.
// 'Get(foo, WithPrefix())' is equal to 'Get(foo, WithRange(GetPrefixRangeEnd(foo))'.
func GetPrefixRangeEnd(prefix string) string {
return string(getPrefix([]byte(prefix)))
}
func getPrefix(key []byte) []byte {
end := make([]byte, len(key))
copy(end, key)
for i := len(end) - 1; i >= 0; i-- {
if end[i] < 0xff {
end[i] = end[i] + 1
end = end[:i+1]
return end
}
}
// next prefix does not exist (e.g., 0xffff);
// default to WithFromKey policy
return noPrefixEnd
}
// WithPrefix enables 'Get', 'Delete', or 'Watch' requests to operate
// on the keys with matching prefix. For example, 'Get(foo, WithPrefix())'
// can return 'foo1', 'foo2', and so on.
func WithPrefix() OpOption {
return func(op *Op) {
if len(op.key) == 0 {
op.key, op.end = []byte{0}, []byte{0}
return
}
op.end = getPrefix(op.key)
}
}
// WithRange specifies the range of 'Get', 'Delete', 'Watch' requests.
// For example, 'Get' requests with 'WithRange(end)' returns
// the keys in the range [key, end).
// endKey must be lexicographically greater than start key.
func WithRange(endKey string) OpOption {
return func(op *Op) { op.end = []byte(endKey) }
}
// WithFromKey specifies the range of 'Get', 'Delete', 'Watch' requests
// to be equal or greater than the key in the argument.
func WithFromKey() OpOption {
return func(op *Op) {
if len(op.key) == 0 {
op.key = []byte{0}
}
op.end = []byte("\x00")
}
}
// WithSerializable makes 'Get' request serializable. By default,
// it's linearizable. Serializable requests are better for lower latency
// requirement.
func WithSerializable() OpOption {
return func(op *Op) { op.serializable = true }
}
// WithKeysOnly makes the 'Get' request return only the keys and the corresponding
// values will be omitted.
func WithKeysOnly() OpOption {
return func(op *Op) { op.keysOnly = true }
}
// WithCountOnly makes the 'Get' request return only the count of keys.
func WithCountOnly() OpOption {
return func(op *Op) { op.countOnly = true }
}
// WithMinModRev filters out keys for Get with modification revisions less than the given revision.
func WithMinModRev(rev int64) OpOption { return func(op *Op) { op.minModRev = rev } }
// WithMaxModRev filters out keys for Get with modification revisions greater than the given revision.
func WithMaxModRev(rev int64) OpOption { return func(op *Op) { op.maxModRev = rev } }
// WithMinCreateRev filters out keys for Get with creation revisions less than the given revision.
func WithMinCreateRev(rev int64) OpOption { return func(op *Op) { op.minCreateRev = rev } }
// WithMaxCreateRev filters out keys for Get with creation revisions greater than the given revision.
func WithMaxCreateRev(rev int64) OpOption { return func(op *Op) { op.maxCreateRev = rev } }
// WithFirstCreate gets the key with the oldest creation revision in the request range.
func WithFirstCreate() []OpOption { return withTop(SortByCreateRevision, SortAscend) }
// WithLastCreate gets the key with the latest creation revision in the request range.
func WithLastCreate() []OpOption { return withTop(SortByCreateRevision, SortDescend) }
// WithFirstKey gets the lexically first key in the request range.
func WithFirstKey() []OpOption { return withTop(SortByKey, SortAscend) }
// WithLastKey gets the lexically last key in the request range.
func WithLastKey() []OpOption { return withTop(SortByKey, SortDescend) }
// WithFirstRev gets the key with the oldest modification revision in the request range.
func WithFirstRev() []OpOption { return withTop(SortByModRevision, SortAscend) }
// WithLastRev gets the key with the latest modification revision in the request range.
func WithLastRev() []OpOption { return withTop(SortByModRevision, SortDescend) }
// withTop gets the first key over the get's prefix given a sort order
func withTop(target SortTarget, order SortOrder) []OpOption {
return []OpOption{WithPrefix(), WithSort(target, order), WithLimit(1)}
}
// WithProgressNotify makes watch server send periodic progress updates
// every 10 minutes when there is no incoming events.
// Progress updates have zero events in WatchResponse.
func WithProgressNotify() OpOption {
return func(op *Op) {
op.progressNotify = true
}
}
// WithCreatedNotify makes watch server sends the created event.
func WithCreatedNotify() OpOption {
return func(op *Op) {
op.createdNotify = true
}
}
// WithFilterPut discards PUT events from the watcher.
func WithFilterPut() OpOption {
return func(op *Op) { op.filterPut = true }
}
// WithFilterDelete discards DELETE events from the watcher.
func WithFilterDelete() OpOption {
return func(op *Op) { op.filterDelete = true }
}
// WithPrevKV gets the previous key-value pair before the event happens. If the previous KV is already compacted,
// nothing will be returned.
func WithPrevKV() OpOption {
return func(op *Op) {
op.prevKV = true
}
}
// WithFragment to receive raw watch response with fragmentation.
// Fragmentation is disabled by default. If fragmentation is enabled,
// etcd watch server will split watch response before sending to clients
// when the total size of watch events exceed server-side request limit.
// The default server-side request limit is 1.5 MiB, which can be configured
// as "--max-request-bytes" flag value + gRPC-overhead 512 bytes.
// See "etcdserver/api/v3rpc/watch.go" for more details.
func WithFragment() OpOption {
return func(op *Op) { op.fragment = true }
}
// WithIgnoreValue updates the key using its current value.
// This option can not be combined with non-empty values.
// Returns an error if the key does not exist.
func WithIgnoreValue() OpOption {
return func(op *Op) {
op.ignoreValue = true
}
}
// WithIgnoreLease updates the key using its current lease.
// This option can not be combined with WithLease.
// Returns an error if the key does not exist.
func WithIgnoreLease() OpOption {
return func(op *Op) {
op.ignoreLease = true
}
}
// LeaseOp represents an Operation that lease can execute.
type LeaseOp struct {
id LeaseID
// for TimeToLive
attachedKeys bool
}
// LeaseOption configures lease operations.
type LeaseOption func(*LeaseOp)
func (op *LeaseOp) applyOpts(opts []LeaseOption) {
for _, opt := range opts {
opt(op)
}
}
// WithAttachedKeys makes TimeToLive list the keys attached to the given lease ID.
func WithAttachedKeys() LeaseOption {
return func(op *LeaseOp) { op.attachedKeys = true }
}
func toLeaseTimeToLiveRequest(id LeaseID, opts ...LeaseOption) *pb.LeaseTimeToLiveRequest {
ret := &LeaseOp{id: id}
ret.applyOpts(opts)
return &pb.LeaseTimeToLiveRequest{ID: int64(id), Keys: ret.attachedKeys}
}